Contactor with a removable arc chute

ABSTRACT

A contactor with a removable arc chute having a clapper plate carrying a movable contact to make and break contact with a fixed contact in accordance with a contact signal applied to an actuator characterized by a latch or safety mechanism for preventing movement of the clapper plate to a position to make contact when the arc chute is removed or displaced from the predetermined position with respect to the contacts. Preferably the latch mechanism also prevents breaking of contact should the arc chute be dislodged. The safety or latch mechanism comprises a pin attached to the clapper plate and having an end surface forming one abutment surface and a second abutment surface formed by a groove in the pin which abutment surfaces coact with edges of a keyhole slot of a slideable plate member carried on the housing of the switch assembly. The plate member with the keyhole slot is movable from a locking position for engaging either the end of the pin or the groove thereof to an unlocking position in which the pin can pass through the wide portion of the keyhole slot. When the arc chute is on the housing in the predetermined position, the chute will hold the sliding plate in the second position enabling free movement of the clapper plate in response to the actuator.

United States Patent 91 Heehler et al.

[ Apr. 17, 1973 CONTACTOR WITH A REMOVABLE ARC CHUTE Inventors: Arthur C. Heehler, Park Ridge, 1., George J. Taylor, Northbrook, lll.

Filed: Oct. 21, 1971 Appl. No.: 191,529

US. Cl. ..200/144 R Int. Cl. ..HOlh 33/46 Field of Search ..200/144 R, 147 R [56] References Cited UNITED STATES PATENTS Doos ..200/144 R Primary Examiner-Robert S. Macon Attorney-Carlton Hill et al.

[ 5 7 1 ABSTRACT A contactor with a removable arc chute having a clapper plate carrying a movable contact to make and break contact with a fixed contact in accordance with a contact signal applied to an actuator characterized by a latch or safety mechanism for preventing movement of the clapper plate to a position to make contact when the arc chute is removed or displaced from the predetermined position with respect to the contacts. Preferably the latch mechanism also prevents breaking of contact should the arc chute be dislodged. The safety or latch mechanism comprises a pin attached to the clapper plate and having an end surface forming one abutment surface and a second abutment surface formed by a groove in the pin which abutment surfaces coact with edges of a keyhole slot of a slideable plate member carried on the housing of the switch assembly. The plate member with the keyhole slot is movable from a locking position for engaging either the end of the pin or the groove thereof to an unlocking position in which the pin can pass through the wide portion of the keyhole slot. When the arc chute is on the housing in the predetermined position, the chute will hold the sliding plate in the second position enabling free movement of the clapper plate in response to the actuator.

l 1 Claims, 5 Drawing Figures CONTACTOR WITH A REMOVABLE ARC CHUTE BACKGROUND OF THE INVENTION 1. Field Of The Invention The present invention is directed to a switch assembly and particularly a heavy duty switch assembly utilizing an arc chute to prevent damage to the contact by arcing.

2. Prior Art Switch assemblies for handling heavy current loads, such as contactors for diesel electric systems such as used in locomotives, have a fixed contact which is engaged by a movable contact carried on a clapper plate or member actuated by actuating means such as a relay solenoid. Due to the heavy current load, arcing will occur at the time of making and breaking contact between the movable and fixed contacts, and the arcing will damage the contact surfaces of both the contacts or cause the contacts to fuse together. It is well known to provide an arc chute with the switch assembly which cute extinguishes the are which may occur during making and breaking of contact in the switch assembly. In certain models, the arc chute is removable to enable access to the contacts and is held in a predetermined position with relation to the fixed contact by a spring detent arrangement. Due to errors occurring in assembling the arc chute on the switch assembly, the chute may not be in the correct position to extinguish the arcing or due to vibrations the chute may be displaced from the correct position and allow arching to occur. Thus with the present switch assemblies or contactors having removable arc chutes, an advertent assembly of thearc chute on the assembly or due to vibration causing the arc chute to be displaced from the correct position, arcing will occur to damage the contacts and the switch assembly.

In the present use of contactors with are chutes in diesel electric systems such as a locomotive, the operator of the locomotive may have a malfunction in his control circuit although the traction motor associated with the particular contactor is operable or in some instances, the control system is operably but a defect has occurred in the traction motor. In most'instances, it would be desirable to have means on the contactor for locking the contacts in either a close position or an open position to override the control circuit provided by the relay of the contactors.

SUMMARY OF THE INVENTION The present invention is directed to an improvement in a switch assembly such as a contactor having an arc chute removably mounted on a housing containing at least one fixed contact and a movable contact carried on a pivotable member mounted in the housing for pivotal movement by an actuator between a position making contact with the fixed contact and a position out of contact therewith. The improvement is the provision of a latch means for selectively preventing the pivotal member from moving to one of its positions and for locking the pivotal member in the one position. Preferably the switching assembly includes an arc chute which is removably mounted on the housing in a desired position with relation to the fixed contact to extinguish any arcing that occurs during making and breaking of the contact. The latching means includes a pin having spaced abutment surfaces attached to the pivotal member and a slideable plate carried in the housing having a pair of abutment surfaces for engaging either one of the pair of oppositely facing abutment surfaces of the pin member to prevent movement of the pivotal member to one position or to lock the member in said one position. The plate member is held by the arc chute when it is positioned on the housing in the correct position to extinguish arcing at the contacts in a position to enable free movement of the pivotal member carrying the movable contact and with removal of the arc chute or accidential displacement thereof the plate member shifts to a position with the abutment surfaces engaging one of the spaced abutment surfaces on the pin member to hold the pivotal member in the predetermined position.

Accordingly it is an object of the present invention to provide a latching mechanism to prevent an arcing between a movable contact and a fixed contact when an arc chute is displaced from a predetermined position.

Another object of the present invention is to provide a latching mechanism for a switch assembly enabling a movable contact to be either locked in one position or prevented from moving to that position.

A still further object of the present invention is to provide a latching mechanism for a switch assembly enabling a movable contact to be locked in either of two positions to override an actuator of the switch assembly.

Many other advantages, features and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a switch assembly of the present invention with the latch mechanism in a disengaged position;

FIG. 2 is a perspective view of the switch assembly of FIG. 1 with a latch mechanism in an engaged position;

FIG. 3 is a partial perspective view of the latch mechanism in an engaged position preventing movement of the contacts to one position;

FIG. 4 is a diagrammatical side view of the switch assembly of the present invention with the latch device illustrated in broken lines in the latching position; and

FIG. 5 is an end view of the switch assembly of FIG. 4 with the latching means illustrated by dotted lines when in the latching position.

DESCRIPTION OF THE PREFERRED EMBODIMENT I The principles of the present invention are particularly useful in a switch assembly indicated at 10 in FIGS. 1 and 2 having a housing 11, supporting an actuator such as relay solenoid 12, an interrupter switch 13 and an arc chute 14. In housing 11, a pivotal member such as a clapper plate or member 15 (best illustrated in FIG. 4) carries a movable contact 16 between a first position withdrawn from a fixed contact 17 and a second position with the movable contact in engagement with the fixed contact 17. Movement to the engaged position is caused by the solenoid 12. Springs such as 18 (FIGS. 1 and 2) acting on a bail 19 force the clipper plate 15 to the open position and the bail 19 moves an actuator plunger 20 to a withdrawn position in the interrupter switch 13. When the actuator 12 draws the clapper plate 15 to a contact closing position, the bail l9 forces a plunger 20 upward to shift contacts in the interrupter switch 13 as the contacts 16 and 17 form an electrical connection.

During the making and breaking of contact between the contacts 16 and 17, arcing will occur. To extinguish the arcing, the arc chute 14 of a conventional structure is removably mounted on the housing 11 and held by a spring detent 21 which engages a bar 22 of the housing 1 1 (best illustrated in FIG. 3) to hold the arc chute in a predetermined position with respect to the fixed contact 17. Since the arc chute 14 is removable, it must be placed on the housing 11 in the correct position in order to effectively extinguish any arcing occurring during making and breaking of contact of the switch assembly with improper mounting the arc chute 14 or with vibrations or jolting causing the detent 21 to come disengaged from the bar 22 enabling displacement of the arc chute 14 from the predetermined position, the arc chute 14 will not function correctly and arcing between the contacts 16 and 17 may cause damage to the switch assembly. The structure of the switch assembly 10 discussed hereinabove is a conventional structure found in contactors utilized in diesel electric systems such as in diesel locomotives.

The present invention is directed to a latch means generally indicated at 25 which is provided in the switch assembly 10 to either lock the clapper plate in an open position as illustrated in FIGS. 2 and 4 or to prevent movement of the clapper plate to the open position as illustrated in FIG. 3. As illustrated in FIG. 4, the latching mechanism 25 comprises a pin 26 attached to the clapper plate 15 which pin has a head 27 providing a pair of oppositely facing abutment surfaces 28 and 29. The latching mechanism 25 also includes a slideable plate member 30 having a keyhole slot 31 (FIG. 3) having a wide portion 32 and a narrow portion 33 whose edges form abutment surfaces for engaging one of the spaced abutment surfaces 28 and 29 of the pin member 26. As illustrated in FIG. 3, the edge portions of the narrow portions 33 are engaging the abutment surface 28 which is the end surfaces of the pin member 26 to prevent movement of the clapper plate 15 to a withdrawn position such as illustrated in FIG. 4. As illustrated in FIG. 2, the edges of the narrow portions 33 engage the abutment surface 29 to lock the clapper plate 15 in the withdrawn position with the movable contact 16 out of contact with the fixed contact 17.

The plate member 30 is slideably carried in a guideway formed by a portion 34 of the housing and a plate 35 of the housing. The plate 35 and the portion 34 in the path of the movement of the pin 26 have cut out or removed portions such as a circular aperture 36 in the plate 35. A channel member 37 is attached to the plate 35 and provides a mounting surface on which the interrupter switch 13 is mounted.

To bias the plate 30 to a position with the narrow portion of the keyhole slot in the path of the pin 26 to either engage the abutment surface 28 or the abutment surface 29 of the pin member, biasing means such as a spring 38 attached to a tab 39 on the plate 30 and a tab or projection 40 on the member 37 is provided. The spring 38 will bias the plate 30 to the position illustrated in dotted lines which is with the narrow portion 33 over lying the aperture 36 to prevent withdrawing of the head 27 or insertion thereof through the aperture.

When the arc chute 14 is assembled on the housing 11 in the correct relation with the fixed contact 17 (FIG. 1), a bottom surface 14a of the chute 14 engages a portion 30a of the plate member 30 to force it against the spring 38 to a postion enabling free movement of the pin into and out of the aperture 36. The portion 30a, as best illustrated in FIG. 3, is offset by a portion 30b from the main portion 30c of the member 30 to provide clearance for the spring detent 21 to engage the bar 22 of the housing 11.'Thus with the arc chute 14 in the corrected position the latch mechanism 25 is held in unlatching or unlocking position.

If the detent 21 due to vibrations or jolting releases the arc chute 14 and allows it to move to be displaced from its desired position as illustrated in FIG. 2, the displacement of the arc chute enables the spring 38 to shift the plate 30 to a latching position to hold the clapper 15 in either a withdrawn position as illustrated in FIG. 2 or to prevent its movement from a position illustrated in FIG. 3. Preferably the spacing or distance between the end 28 and the abutment surface 29, which may be formed by providing a groove in the pin 26, is selected so that movement of the plate member 30 to a position blocking passage of the pin through the aperture 36 will also hold the movable contact 16 on the contact 17 to prevent breaking of the contacts and a breaking are that would occur therewith. The pin 26 is preferably secured to the clapper plate 15, by threads which enable adjusting the position of the abutment surface 28 with respect to the surface of the contact 16 to maintain engagement between the contacts 16 and 17 when the plate member 30 is shifted to prevent passage of the pin 26 through the aperture 36.

As mentioned hereinabove, during the operation of a system utilizing a contractor switch assembly, the operator may have a faulty traction motor and, to minimize damages thereto, the operator may desire to lock the clapper plate 15 of the switch assembly 10 in the withdrawn or opened position which is illustrated in FIG. 4. This can be accomplished by removing the arc chute 14 and shifting the clapper plate 15 to the withdrawn position and allowing the plate 30 to move to the locking position. In a similar manner, the operator may desire to lock the contacts 16 and 17 in the engaged or contacting position which is accomplished by removing the arc chute 14, depressing or holding the plate member 30 in an unlatched position and manually shifting the clapper plate 15 to a engaged position and then releasing the 'plate member 30. Thus the latch mechanism besides providing a safety device to prevent arcing between the contacts due to an inadvertent or accidential displacement of the arc chute from the proper position also enables a manual override for locking the switch assembly in a closed position or an open position as desired.

While this discussion of a preferred embodiment of the invention deals with a single pole-single throw switch the latching mechanism can be utilized in switching assemblies which are double throw double pole switches have are chutes. In a double throw double pole switch assembly, displacement of the arc chute causes the latch device to lock the pivoted member and prevents its further movement.

Although various modifications may be suggested by those versed in the art, it should be understood that we wish to employ within the scope of the patent warranted hereon all such embodiments as reasonably and properly come with in the scope of our contribution to the art.

We claim:

1. An electrical switch assembly having a housing containing at least one fixed contact and a movable contact carried on a member pivotally mounted for movement in the housing by an actuator between a pair of positions with a position of the pair having the movable contact in engagement with the fixed contact and the other position of the pair with the movable contact out of engagement with the fixed contact, the improvement comprising latch means for selectively preventing movement of said member to one of said pair of positions and for selectively locking said member in said one position.

2. An electrical switch assembly according to claim 1, wherein said latch means, while selectively preventing movement of the pivotal member to said one position of said pair, locks said member in said other position of the pair of positions.

3. An electrical switch assembly having a housing containing at least one fixed contact and a movable contact carried on a member pivotally mounted for movement in the housing by an actuator between a pair of positions with a position of the movable contact in engagement with the fixed contact and the other position of the pair with the movable contact out of engagement with the fixed contact, the improvement comprising latch means for selectively proventing movement of said member to one of said pair of positions and for selectively locking said member in said one position, said latch means includes a pin member having a pair of oppositely facing abutment surfaces secured to the pivotal member and a plate member having abutment surface, said plate member being slideably mounted in said housing for movement from a first position with the abutment surfaces of the plate member engaging one of said pair of oppositely facing abutment surfaces of the pin member to a second position with the abutment surfaces of the plate member withdrawn from a position for engagement with the abutment surfaces of the pin member so that movement of the plate member to said first position either locks the pivotal member in the one position or prevents movement of the pivotal member to the said one position and movement of the plate member to the second position enables freedom of movement for the pivotal member between its pair of positions.

4. An electrical switch assembly according to claim 3, wherein the latch means further includes means biasing the plate member to said first position.

5. An electrical switch assembly accordingly to claim 3, wherein the plate member has a keyhole slot with an enlarged portion of the slot having a size to enable passage of the pair of abutment surfaces of the pin member therethrough and with a narrow portion of the plate member is biased towards a position preventing movement of the pivotal member.

7. An electrical switch assembly according to claim 6, which includes an arc chute removeably carried on .the housing of the switch assembly for extinguishing any arcing occurring during making and breaking contact between the movable and fixed contacts, said plate member of the latch means being held in the second position by the placement of the arc chute on the housing in the proper position so that removal of the arc chute or misalignment thereof enables the plate member to move to the first position to prevent movement of the pivotal member.

8. An electrical switch assembly having a housing containing at least one fixed contact, movable contact carried on a clapper member pivoted between a pair of positions in the housing by an actuator means carried by the housing a first of said pair of positions having the movable contact in engagement with the fixed contact and a second position of said pair having the movable contact out of engagement with the fixed contact, said assembly including an arc chute removably mounted on the housing in a predetermined position with respect to the fixed contact to extinguish any arcing occurring during making and breaking of contact between said movable and fixed contacts, the improvement comprising latch means for selectively locking said clapper member in said first and second positions when the arc chute is displaced from the predetermined position by either being removed from the housing or accidentially dislodged from the predetermined position.

9. An electrical switch assembly having a housing containing at least one fixed contact, a movable contact carried on a clapper member pivoted between a pair of positions in the housing by an actuator means carried by the housing, one of said pair of positions having the movable contact in engagement with the fixed contact and the other position having the movable contact out of engagement with the fixed contact, said assembly including an arc chute removably mounted on the housing in a predetermined position with respect to the fixed contact to extinguish any arcing occurring during the making and breaking of contact between said movable and fixed contacts, the improvement comprising latch means for selectively preventing movement of said clapper member to one of said pair of positions and for selectively locking said clapper member in said one position when the arc chute is displaced from the predetermined position by either being removed from the housing or accidentially dislodged from the predetermined position, said latching means includes a pin member having a pair of opposite facing abutment surfaces secured to the clapper member and a plate member having abutment surfaces being movably mounted in said housing for movement between a first position with the abutment surfaces of the plate member engaging one of the said pair of oppositely facing abutment surfaces of the pin member to a second position with the abutment surfaces of the plate member withdrawn from a position for engagement with the abutment surfaces of the pin member, and means biasing the plate member to said first position with the arc chute holding the plate member in the second position when the arc chute is in the predetermined position so that with the arc chute in the predetermined position, the clapper member is free to move between said pair of positions and with displacement of the arc chute from the predetermined position said abutment surfaces of the plate member locks the clapper member in said one position or prevent movement of the clapper member to said one position.

10. An electrical switch assembly according to claim 9, wherein said space abutment surfaces on said pin member have a distance therebetween so that engagement of one of said spaced abutment surfaces with the abutment surfaces of the plate member hold the clapper member in said one position and engagement of the other spaced abutment surface with the abutment surfaces of the plate member hold the clapper member in the other of said pair of positions.

11. An electrical switch assembly according to claim 10, wherein said plate member has a keyhole aperture with an enlarged portion and a narrow portion, said enlarged portion being of a size to enable passage of the pin member therethrough and said narrow portion having edges providing the abutment surfaces of said plate member, said aperture being positioned so that the narrow portion is in the path of the pin member when the plate member is in said first position and the enlarged portion is in the path of the pin when said plate member is in the second position. 

1. An electrical switch assembly having a housing containing at least one fixed contact and a movable contact carried on a member pivotally mounted for movement in the housing by an actuator between a pair of positions with a position of the pair having the movable contact in engagement with the fixed contact and the other position of the pair with the movable contact out of engagement with the fixed contact, the improvement comprising latch means for selectively preventing movement of said member to one of said pair of positions and for selectively locking said member in said one position.
 2. An electrical sWitch assembly according to claim 1, wherein said latch means, while selectively preventing movement of the pivotal member to said one position of said pair, locks said member in said other position of the pair of positions.
 3. An electrical switch assembly having a housing containing at least one fixed contact and a movable contact carried on a member pivotally mounted for movement in the housing by an actuator between a pair of positions with a position of the pair having the movable contact in engagement with the fixed contact and the other position of the pair with the movable contact out of engagement with the fixed contact, the improvement comprising latch means for selectively proventing movement of said member to one of said pair of positions and for selectively locking said member in said one position, said latch means includes a pin member having a pair of oppositely facing abutment surfaces secured to the pivotal member and a plate member having abutment surfaces, said plate member being slideably mounted in said housing for movement from a first position with the abutment surfaces of the plate member engaging one of said pair of oppositely facing abutment surfaces of the pin member to a second position with the abutment surfaces of the plate member withdrawn from a position for engagement with the abutment surfaces of the pin member so that movement of the plate member to said first position either locks the pivotal member in the one position or prevents movement of the pivotal member to the said one position and movement of the plate member to the second position enables freedom of movement for the pivotal member between its pair of positions.
 4. An electrical switch assembly according to claim 3, wherein the latch means further includes means biasing the plate member to said first position.
 5. An electrical switch assembly according to claim 3, wherein the plate member has a keyhole slot with an enlarged portion of the slot having a size to enable passage of the pair of abutment surfaces of the pin member therethrough and with a narrow portion of the slot providing the abutment surfaces for engagement of the abutment surfaces of the pin member, so that movement of the plate member to the first position places the narrow portion of the keyhole slot in the path of the pin member and movement of the plate member to the second position places the enlarged portion of the keyhole slot in the path of the pin member.
 6. An electrical switch assembly according to claim 5, wherein said latch means further includes means biasing the plate member toward the first position so that the plate member is biased towards a position preventing movement of the pivotal member.
 7. An electrical switch assembly according to claim 6, which includes an arc chute removeably carried on the housing of the switch assembly for extinguishing any arcing occurring during making and breaking contact between the movable and fixed contacts, said plate member of the latch means being held in the second position by the placement of the arc chute on the housing in the proper position so that removal of the arc chute or misalignment thereof enables the plate member to move to the first position to prevent movement of the pivotal member.
 8. An electrical switch assembly having a housing containing at least one fixed contact, movable contact carried on a clapper member pivoted between a pair of positions in the housing by an actuator means carried by the housing a first of said pair of positions having the movable contact in engagement with the fixed contact and a second position of said pair having the movable contact out of engagement with the fixed contact, said assembly including an arc chute removably mounted on the housing in a predetermined position with respect to the fixed contact to extinguish any arcing occurring during making and breaking of contact between said movable and fixed contacts, the improvement comprising latch means for selectively locking said clapper member in said first anD second positions when the arc chute is displaced from the predetermined position by either being removed from the housing or accidentially dislodged from the predetermined position.
 9. An electrical switch assembly having a housing containing at least one fixed contact, a movable contact carried on a clapper member pivoted between a pair of positions in the housing by an actuator means carried by the housing, one of said pair of positions having the movable contact in engagement with the fixed contact and the other position having the movable contact out of engagement with the fixed contact, said assembly including an arc chute removably mounted on the housing in a predetermined position with respect to the fixed contact to extinguish any arcing occurring during making and breaking of contact between said movable and fixed contacts, the improvement comprising latch means for selectively preventing movement of said clapper member to one of said pair of positions and for selectively locking said clapper member in said one position when the arc chute is displaced from the predetermined position by either being removed from the housing or accidentially dislodged from the predetermined position, said latch means includes a pin member having a pair of opposite facing abutment surfaces secured to the clapper member and a plate member having abutment surfaces being movably mounted in said housing for movement between a first position with the abutment surfaces of the plate member engaging one of the said pair of oppositely facing abutment surfaces of the pin member to a second position with the abutment surfaces of the plate member withdrawn from a position for engagement with the abutment surfaces of the pin member, and means biasing the plate member to said first position with the arc chute holding the plate member in the second position when the arc chute is in the predetermined position so that with the arc chute in the predetermined position, the clapper member is free to move between said pair of positions and with displacement of the arc chute from the predetermined position said abutment surfaces of the plate member locks the clapper member in said one position or prevent movement of the clapper member to said one position.
 10. An electrical switch assembly according to claim 9, wherein said space abutment surfaces on said pin member have a distance therebetween so that engagement of one of said spaced abutment surfaces with the abutment surfaces of the plate member hold the clapper member in said one position and engagement of the other spaced abutment surface with the abutment surfaces of the plate member hold the clapper member in the other of said pair of positions.
 11. An electrical switch assembly according to claim 10, wherein said plate member has a keyhole aperture with an enlarged portion and a narrow portion, said enlarged portion being of a size to enable passage of the pin member therethrough and said narrow portion having edges providing the abutment surfaces of said plate member, said aperture being positioned so that the narrow portion is in the path of the pin member when the plate member is in said first position and the enlarged portion is in the path of the pin when said plate member is in the second position. 